UPC -A Barcodes are used for marking products sold in stores throughout the USA and Canada. The barcode is comprised of three groupings of numbers, the manufacturer ID (the company who owns the barcode prefix) which is 6, 7, 8 or 9 digits in length, the balance of numbers totaling 11 digits and the final 12th number (Check Digit or Checksum). The check digit is based on a mod 10 formula.

More detailed breakdown about UPC:

What it is: A UPC is a 12-digit barcode that uniquely identifies a product and its manufacturer.

How it works: Retailers and logistics third parties scan these unique UPCs to import price data and track inventory.

Why it's important: UPCs are essential for selling products through physical and online marketplaces, enabling efficient tracking and inventory management throughout the supply chain.

UPC-A: The most common type of UPC barcode, consisting of 12 digits.

GTIN-12: The 12-digit numerical code that the UPC-A barcode encodes.

Global Standard: UPCs are part of the GS1 global standards and are accepted worldwide.

EAN vs UPC: While UPCs are used in North America, the rest of the world primarily uses EAN (European Article Number) barcodes, which are also part of the GS1 system.

Structure of a UPC-A:

Company Prefix: The first 6-9 digits, assigned by GS1 (formerly the Uniform Code Council).
Product Numbers: Uniquely identify individual items.
Check Digit: The last digit, used for error detection.

EAN, EAN-13, European Article Number, International Article Number)

An EAN-13 barcode (originally European Article Number, but now renamed International Article Number) is a 13 digit (12 data and 1 check-digit) barcoding standard which is a superset of the original 12-digit Universal Product Code (UPC) system developed in the United States. The EAN-13 barcode is defined by the standards organization GS1. Aside from the additional digit, the big difference is that an ean has a visible country code.

More detailed breakdown about EAN:

What it is: EAN stands for European Article Number, and EAN-13 is the most common variant, a 13-digit barcode system used worldwide for identifying products at retail.

How it works:
i. The 13-digit number is encoded in a barcode, which is typically printed on product packaging.
ii. When scanned at a point of sale, the barcode data is used to look up product information like price and description.
iii. EAN-13 is a GTIN-13 (Global Trade Item Number).